Method of cleaning flexible foraminous sheets



F. G. PURINTON METHOD 0F CLEANING FLEXIBLE FORAMINOUS SHEETS Filed Nov. 21, '1927 Figl. f Y y \nvenor. f y Forres GFurnTon bymwkw ATyS.

Patented Dec. 4, 1928.

UNITED STATES FORREST G. PURINTON, OF WATERBURY, CONNECTICUT,

ASSIGNOR TO THE IATENT BUTTON-COMPANY, OF WATERBURY, CONNECTICUT, A CORPORATION OF CON- NECTICUT. i

METHOD OF CLEANING FLEXIBLE FORAMINOUS SHEETS.

Application filed November 21, 1927. Serial No.v 234,570.

This invention relates to a method of cleaning soluble material and particularly soluble solid coatings from the surface of a flexible sheet of foraminous orreticulated material.

More particularly the invention relates to improvements in the method of cleaning a coating of soluble material, suoli as pyroxylin, paint, lacquer or, particularly, the coating composition commercially known as Duco7 coating from a reticulated wire screen which has been used to support articles during the painting or coating thereof by anV air brush, or other spraying device,and `for salvaging the coating material.

The invention is particularly adapted to be employed forthel cleaning of screens of a button coating machine such as that disclosed in my prior application Serial No. 153,512 iiled December 9, F1926. The machine disclosed in that application comprises a hopper.

to contain a mass of buttons, or like articles, having differing vobverse and reverse faces, with means for assembling articles in closely Yseparated juxtaposition, with like faces exl posed, andmeans .for transferring such -articles-in theirassembled position to an endless screen which passesthrougha painting ieldin which a coatingof Duco, or other Vsuitable liquid material, is applied to the articles, Vand which endless screen thence .passes througha drier in which the volatile solvent of the coating is vaporized vand re moved and the driedarticles thereafter -de posited in a suitable receptacle. In thecourse of time the coatingmaterial deposited-upon the traveling-endless screen ,by the painting mechanism, and baked thereupon by the drier, partially'or `wholly iills many of the meshes of the "screen, thus interfering` with the proper `paintin, ;'^of the articles by obstructing the passages through Vwhich the paint not depositedupon the articles is intendedto pass and cansingan undesirable accumulation of coating material upon the screen whichis likely tocause the buttons, or other articles, to adhere to itzand also to cause undesirable accumulation of coating in the eyes of the buttons. A,Such screens may be `quickly and'economically cleaned by the method and apparatus forming the subject matter of this invention and the coating ma- -terial carried by the screen salvaged.,

The present method broadly stated comject all portions of the surface of the sheet .p

to the action ofthe solvent and to maintain a continuous agitation of the solvent. Desiri ably the solvent is subjected to the influence of a force rotating in the samedirection as that of the scroll to causethe liquid, in its elfort to maintain its level, to flow in directions transversely ofthe axis of the scroll,

.thereby flowing upon the several spirals of the sheet and through the perforations therein so that all of the surfaces of thesheet and the coating thereupon are subjected to the action of the solvent. Furthermore, the solvent is so agitated that stratification of any portion thereof, which otherwise might become a saturated solution, isavoided.

The rotating force acting upon the liquid solvent may be conveniently applied by enclosing the solvent in a cylindrical rotating drum or barrel and introducing the foraminous sheet, when` rolled into the form of a cylindrical scroll, into tlie'barrel so that its periphery rests upon the inner surface of the barrel, and then rotating the barrel. The rotation of the barrel will rotate the scroll by reason of its frictional contact with thek periphery of the scroll and the friction and adhesion between the liquid solvent and the inner face of the wall of the barrel will in effect cause the' application lof a rotative force to the liquid solvent which will tend to rotate the ,body of solvent inthe same direction as the direction of rotation ofthe screen. This rotative force carries the liquid of the solvent upwardly-along the barrel at one side of the axisso that the liquid in its tendencyV to seek its level will -flow downwardly in di`-` rections transversely of the axis of the scroll and through the perforations therein, thereby subjecting` the ventire surface of the sheet and the walls'of the apertures therethrough to the solvent so that any coating material which may be adherent-to the sheet will be removed by the action of the solvent. Desirably the drum is rotated with sutlicient rapidity to causemore or less cascading of the solvent upon the screen so that the impingement of the liquid upon the coating will more readily dissolve it. Y

The preferred form of apparatus for performing the method herein described is illustrated in the accompanying drawings, in which,

Fig. 1 is an end view of a barrel containing Y V a solvent for the coating material and illustrating in dotted lines a screen rolled into the form of a Scroll and means for rotating the barrel;

Fig. 2 is a side elevation of the same, a portion of the wall of the barrel being broken a-Way to show the liquid solvent and the scroll of wire screen; and,

Fig. 3 is a detail view illustrating a convenient method of detachably securing one of the heads to the barrel.

The apparatus illustrated in the accompanying drawingscomprises a drum 1 having the form of a barrel and preferably made of sheet metal. The barrel may be provided with an integral head 2 and with a detachable head 3 which, as illustrated herein, is secured upon the opposite end or head of the barrel by a divided clamping ring 4 having laterally extending flanges 5 and 6 which are connected biy a screw 7 adapted when manipulated to c amp the ring upon thebarrel and to permit it to be released therefrom. The clamping ring is of arcuate cross section as illustrated in Fig. 3 and is adapted at one side to engage the beveled edge 8 of the headof the barrel and at its opposite side to engage a bead 9 formed upon the end of the barrel. A sealy ing gasket 10 desirably is interposed between the ring and head and is irmlyv clamped therebetween when the ring 4 is contracted by the setting up of the screw 7 The barrel 1 is rotatably supported upon y oppositely disposed pairs of rollers 11 and 12 Vwhich are iixedly secured yto shafts 13 and 14 mounted respectively in bearings 15 and 16 carried by suitable bed plates 17 and 18. The shafts 13 and 14 are extended beyond the end of the barrel and have secured to them sprockremoved from its supporting rolls and stood `on its base or head 2. It is then partially filled with a liquid solvent for the material which is to be removed from the screen; tor example, if a pyroxylin coating material, such as Duco is to be removed from the foralninous sheet or screen, gasoline, acetone, or other suitable solvent Yfor the material may f be introduced into the barrel.

The foraniinous sheet or screen to be treated is rolled into the forni oi' a cylindrical scroll, the outer end of the sheet being secured to the scroll in such a manner that it will not spring' away 'trom it and the scroll placed in the barrel. The head 3 ot' the barrel is then replaced and clamped upon the barrel by the clamping ring 9. When thus assembled the barrel is placed upon its side upon the pairs of rollers 11 and 12'and Vrota.- tion imparted toV these rollers through the sprocket wheels and sprocket chains. The rotation thus imparted to the barrel causes the foraininous or wire screen scroll-to rotate about the axis of thescroll and the adhesion and friction between the wall of the if barrel and the liquid causes the liquid to rise u with the ascending portion ofthe wall oiJ the barrel and if the speed' of rotation is sufficiently rapid causes the liquid to cascade down upon the screen. The liquid displaced from its normal level by such rotative movement tends again to seek its level and thereby flows in directions transversely with respect to the axis of the scroll. The liquid carried up along the ascending portions of the converging ends of the barrel will'tend to flow toward the longitudinal center of the barrel to a greater or less extent, thereby augmenting the iiow against the outer face of the scroll, and also assisting in agit-ating the solvent.

The rotation of the screen `itself within the barrel serves also to agitate the Vsolvent in the barrel and to car more or less of the solvent above its norma level so that a considerable portion thereof passes throuffh the apertures of the sheet. By virtue of the agitation of the solvent produced by the rotation of the barrel and the screen, saturation of any portion ofthe solvent is prevented and the entire body of solvent caused to act uniformly upon the sheet of foraminous material. By virtue of this action the foraminous or reticulated sheet is very quickly cleaned. It is then removed from the drum by merely removing the head of the drum and withdrawing the scroll which can then be `unwound and again applied to the painting machine. The solvent which has been more or less saturated with the coating material may then be poured-out of the barrel and again employed to make the coating mixture by the additionV of sullicient coating material thereto to produce the properV con sistency for use in the air brush, or other projecting device.

It will be understood that the particular apparatus disclosed herein is of an illustrative cb aracter, and that other forms of apparatus may be employed in the performance of the `method herein described, and that such modifications in the method and apparatus may be made as Will fall Within the scope yand meaning of the following claims.

l. The method of cleaning soluble material form a flexible foraminous sheet which comprises rolling said sheet into the form of a scroll, rotating said scroll and subjecting the same to the action of a moving liquid solvent for said material.

2. The method of cleaning soluble material from a flexible foraminous sheet which comprises rolling said sheet into the form of a scroll, continuously rotating said scroll about its axis in a bath of a liquidsolvent for said material to subject all portions of the surface of said sheet to the action of the solvent and to maintain continuous agitation of the solvent.

3. The method of cleaning soluble material from a flexible oraminous sheet which consists in rolling` said sheet into the form of a scroll, partially immersing the scroll in a bath of liquid solvent for the material, rotating said scroll about its axis and subjecting said liquid solvent to the influence of a force rotating in the same direction as that of the scroll to cause the liquid to 'flow upon and through the foraminous sheet in directions transversely of the axis of the scroll.

4. The method of cleaning a soluble coating from a Wire screen Whichcomprises rolling the screen longitudinally into the form of a scroll, partially immersing the scroll in a bath of liquid solvent for said coating, continuously rotating the scroll aboutk its axis and causing the solvent to cascade upon the scroll.` c

In' testimony whereof, I have signed'my name to this specification.

FORREST Gr. PURINTON. 

